What is a common indicator of fuel contamination?

Changes in color or the presence of sediment are indeed common indicators of fuel contamination. When fuel becomes contaminated, either with water, dirt, or other particulates, its appearance can change markedly. For instance, clean fuel typically has a consistent color and clarity. If contamination occurs, one might notice a discoloration, which could be indicative of either microbial growth or the presence of water and particulates within the fuel. Sediment accumulation is also a clear sign, as these particles can settle at the bottom of a fuel storage tank, leading to operational issues.

While unusual odor, increased viscosity, and fuel temperature fluctuations can also suggest problems with fuel, they are not as direct or specific as changes in color or sediment presence. For instance, an unusual odor might indicate a breakdown in the fuel but could stem from various sources—not solely contamination. Increased viscosity, often a result of temperature changes or fuel degradation, does not specifically pinpoint contamination. Fuel temperature fluctuations can signify environment-based issues or equipment function, rather than directly indicating fuel quality. Thus, changes in color and sediment presence provide the most concrete evidence of contamination.